What makes a "hardy" and "non-hardy" fish.

[zacjeff]

I was pondering the meaning of life the other day, when I came up with this question:

1) Is a hardy fish one who's requirements are easy to meet, such as a neon tetra, and a not-so-hardy fish one who's requirements are more difficult, such as a RTC (tank size) or Mandarinfish (diet).

OR​

2) Is a hardy fish any fish who will thrive as long as its requirements are met, like most fish, and a not-so-hardy fish one who will not necessarily thrive even if all of its requirements are met, like a Moorish Idol or a Blue Ribbon Eel.

Just wondering. Ideas?​

 

[Pyramid_Party]

It sounds about right. But I usually associate hardiness with how tolerable a fish is with things like:

PH Range
Temp Range
Oxygen levels
Levels of Ammonia, NitrIe and NitrAte


A hardy fish should be measured with how well it tolerates a wide range of PH and Temp. Also lower levels of oxygen and some presence of Levels of Ammonia, NitrIte and NitrAte.


For example, a common goldfish is a very hardy fish. Whereas something like a Discus or Shrimp is sensitive.

 

[IKeepPacu]

i feel pretty much the sme way as the above poster.

a hardy fish is something like goldfish, pacu and many ca/sa cichlids. fish that can tolerate different ranges of parameters, eat anything and everything, and are forgiving with mistakes being made IE...not enough water changes, temp fluctuating.

non hardy fish are stingrays, discus, many scaleless fish and most marine animals. these are the ones that NEED a very specific range of parameters, specific foods, and will suffer greatly, or worse very fast, if anything in the tank slightly goes out of balance.

 

[hybridtheoryd16]

The same as above and also, If a fish is easily stressed to the point of disease or not.

 

[Ricko]

I was pondering the meaning of life the other day, when I came up with this question:

1) Is a hardy fish one who's requirements are easy to meet, such as a neon tetra, and a not-so-hardy fish one who's requirements are more difficult, such as a RTC (tank size) or Mandarinfish (diet).

OR​

2) Is a hardy fish any fish who will thrive as long as its requirements are met, like most fish, and a not-so-hardy fish one who will not necessarily thrive even if all of its requirements are met, like a Moorish Idol or a Blue Ribbon Eel.​

Just wondering. Ideas?​

IMO a hardy fish is one that is not sensitive to slight water chemistry changes, temperature, high nitrate, etc, (as someone else has said i believe).
Also while i'm here, Moorish Idols are extremely hardy, it is just hard to find one that has been shipped well and coped with it.

 

[Lupin]

My perspective is shared by Pyramid_Party's. I measure 'hardiness' level based on the tolerance for changes in water chemistry and other factors that influence their wellbeing.

 

[cichlid2006]

ive always been led to believe that a hardy fish is a fish that can take unbelieveable amounts of abuse that you see from ignorant and uneducated fishkeepers. such as the common goldfish can take a few years of 100% chlorinated water changes in a filterless and often airstone-less bowl before it dies. thats the Arnie of fish IMO. oscars are a close 2nd for the most abused fish that will take it for years before it dies.

something like guppies nowadays die if you sneeze too hard next to the tank. this would be a less hardy fish IMO and experience. they used to be one of toughest fish going and a good beginner fish when i started fishkeeping in the late 80's.

 

[Lupin]

Their hardiness can be influenced by how they were bred. There are a few fish that are often mated with their parents to obtain the strain they want. Black melano bettas apparently are given this practice thus these ones have the reputation for being difficult to keep. These strains are very rare in the trade. I don't think many have seen nor obtained a solid black betta.

 

[Yanbbrox]

L46 pleco for example is getting less and less hardy due to the gene pool being so small now. Breeding from the same fish over and over again with out mixing the genes causes this.

 

[cichlid2006]

dwarf gouramies are so weak now as well. the amount of inbreeding to obtain the best colours is ridiculous. i remember going to buy my first one a few years ago and the guy in the shop warned me that i would probably get 6 months max out of the fish and that was with good care. it turned out it lived for 8 months so at least it beat the odds slightly.
in fact in the last few years a lot of the old school hardier species and first fish, such as guppies, neons, rams, cardinals, angels etc, are becoming more and more difficult to keep. at least thats what ive noticed in the uk in the areas where ive lived. it is ultimately due to the massive inbreeding and the lack of new wild genes restocking the gene pool.